The latest episode of Criminal Minds: Evolution Season 4 takes the BAU into dark, occult territory—a realm the series hasn't explored in years. Episode 4 delivers a gruesome case-of-the-week that feels ripped from medieval folklore, while simultaneously setting the stage for the season's big bad: the Fan. This copycat killer has been lurking in the shadows, but now he's firmly on the team's radar, and with Elias Voit (Zach Gilford) still alive and imprisoned, the rules of engagement have shifted dramatically.
A Witch Hunt in Modern Day
The episode opens with a chilling scene: an unsub swings a sledgehammer at a woman while her husband is forced to watch. The attacker screams for a confession of heresy, a vial of salt hanging around his neck. The BAU quickly learns the unsub waits until the children leave the house, targets couples, and demands a specific admission. Prentiss (Paget Brewster) connects the dots—the occult references, the trial-like atmosphere, the violence against women—and lands on witch hunts.
When the unsub strikes again, this time killing the husband and leaving the wife alive, the team discovers the victims were all involved in extramarital affairs. Rossi (Joe Mantegna) digs up a medieval text called the Hammer of Witches, which equates infidelity with witchcraft. The profile emerges: a highly educated man, obsessed with this text, who appears non-threatening and has personal issues with cheating. Rossi even uses the term "moral enforcer," a nostalgic callback to classic Criminal Minds profiling categories.
The Teacher Connection
The final piece of the puzzle comes when the team realizes the unsub waits for children to leave—because he's a substitute teacher. He forms bonds with kids, learns about their parents' affairs, and uses their schedules to plan the murders. The BAU stops his latest attack just in time, and Green (Ryan-James Hatanaka) takes him down. While not the most complex case of the season, the ritualistic imagery makes it unforgettable.
J.J.'s Domestic Struggles and a New Mentorship
Meanwhile, J.J. (A.J. Cook) continues navigating life without her husband, Will. This episode focuses on her relationship with her son Henry (Mekhai Anderson), who is considering staying local for college instead of moving to California. Their ice cream chat is a bit awkward, but it offers a comforting glimpse into J.J.'s personal life.
More exciting is the budding mentorship between Rossi and Green. For the first time since Reid and Gideon in Season 1, we see a senior agent take a rookie under his wing. Rossi encourages Green to share his theories, even when they're off-base, helping him "get his reps in." Their dynamic—Green's self-doubt versus Rossi's teasing confidence—makes for engaging, fun scenes.
The Fan Makes His Move
Elsewhere, Lewis (Aisha Tyler) continues her psychological analysis of Voit, but things take a turn when he shows her the pages he received from the Fan. The season's overarching villain is no longer just a shadow—he's actively communicating with Voit, and the BAU is now in a race to stop them both.
For more on the season's twists, check out our recap of Episode 3. And if you're a fan of chilling villains, don't miss our ranking of the most terrifying psychopaths in movie history.
